/*
** $Id: lobject.h,v 2.117.1.1 2017/04/19 17:39:34 roberto Exp $
** Type definitions for Lua objects
** See Copyright Notice in lua.h
*/

#ifndef lobject_h
#define lobject_h

#include <stdarg.h>

#include "llimits.h"
#include "lua.h"

/*
** Extra tags for non-values
*/
#define LUA_TPROTO LUA_NUMTAGS /* function prototypes */
#define LUA_TDEADKEY (LUA_NUMTAGS + 1) /* removed keys in tables */

/*
** number of all possible tags (including LUA_TNONE but excluding DEADKEY)
*/
#define LUA_TOTALTAGS (LUA_TPROTO + 2)

/*
** tags for Tagged Values have the following use of bits:
** bits 0-3: actual tag (a LUA_T* value)
** bits 4-5: variant bits
** bit 6: whether value is collectable
*/

/*
** LUA_TFUNCTION variants:
** 0 - Lua function
** 1 - light C function
** 2 - regular C function (closure)
*/

/* Variant tags for functions */
#define LUA_TLCL (LUA_TFUNCTION | (0 << 4)) /* Lua closure */
#define LUA_TLCF (LUA_TFUNCTION | (1 << 4)) /* light C function */
#define LUA_TCCL (LUA_TFUNCTION | (2 << 4)) /* C closure */

/* Variant tags for strings */
#define LUA_TSHRSTR (LUA_TSTRING | (0 << 4)) /* short strings */
#define LUA_TLNGSTR (LUA_TSTRING | (1 << 4)) /* long strings */

/* Variant tags for numbers */
#define LUA_TNUMFLT (LUA_TNUMBER | (0 << 4)) /* float numbers */
#define LUA_TNUMINT (LUA_TNUMBER | (1 << 4)) /* integer numbers */

/* Bit mark for collectable types */
#define BIT_ISCOLLECTABLE (1 << 6)

/* mark a tag as collectable */
#define ctb(t) ((t) | BIT_ISCOLLECTABLE)

/*
** Common type for all collectable objects
*/
typedef struct GCObject GCObject;

/*
** Common Header for all collectable objects (in macro form, to be
** included in other objects)
*/
// next: for link to g->allgc list, maybe in g->finobj, g->tobefnz, g->fixedgc
// tt: actual tag type + variant tag type
// marked: gc colors
#define CommonHeader \
  GCObject* next; \
  lu_byte tt; \
  lu_byte marked

/*
** Common type has only the common header
*/
struct GCObject {
  CommonHeader;
};

/*
** Tagged Values. This is the basic representation of values in Lua,
** an actual value plus a tag with its type.
*/

/*
** Union of all Lua values
*/
typedef union Value {
  GCObject* gc; /* collectable objects */
  void* p; /* light userdata */
  int b; /* booleans */
  lua_CFunction f; /* light C functions */
  lua_Integer i; /* integer numbers */
  lua_Number n; /* float numbers */
} Value;

// tt_ means a tag with value_'s type, GCObject.tt_ + collectable
#define TValuefields \
  Value value_; \
  int tt_

typedef struct lua_TValue {
  TValuefields;
} TValue;

/* macro defining a nil value */
#define NILCONSTANT {NULL}, LUA_TNIL

#define val_(o) ((o)->value_)

/* raw type tag of a TValue */
#define rttype(o) ((o)->tt_)

/* tag with no variants (bits 0-3) */
#define novariant(x) ((x)&0x0F)

/* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */
#define ttype(o) (rttype(o) & 0x3F)

/* type tag of a TValue with no variants (bits 0-3) */
#define ttnov(o) (novariant(rttype(o)))

/* Macros to test type */
// base check
// bit6         bit5,4        bit3,2,1,0
// collectable  variant type  lua base type
// checktag: all bit, checktype: only bit0-3
#define checktag(o, t) (rttype(o) == (t))
#define checktype(o, t) (ttnov(o) == (t))
// Number, base tag type, Non collectable
#define ttisnumber(o) checktype((o), LUA_TNUMBER)
// float and int belong to number
#define ttisfloat(o) checktag((o), LUA_TNUMFLT)
#define ttisinteger(o) checktag((o), LUA_TNUMINT)

#define ttisnil(o) checktag((o), LUA_TNIL)
#define ttisboolean(o) checktag((o), LUA_TBOOLEAN)
#define ttislightuserdata(o) checktag((o), LUA_TLIGHTUSERDATA)
// String, all string are collectable
#define ttisstring(o) checktype((o), LUA_TSTRING)
// short string, long string
#define ttisshrstring(o) checktag((o), ctb(LUA_TSHRSTR))
#define ttislngstring(o) checktag((o), ctb(LUA_TLNGSTR))

#define ttistable(o) checktag((o), ctb(LUA_TTABLE))
// Function, Contain light C function, C closure, Lua closure
#define ttisfunction(o) checktype(o, LUA_TFUNCTION)
// Closure, Contain C closure, Lua closure, collectable
#define ttisclosure(o) ((rttype(o) & 0x1F) == LUA_TFUNCTION)
// C closure and Lua closure
#define ttisCclosure(o) checktag((o), ctb(LUA_TCCL))
#define ttisLclosure(o) checktag((o), ctb(LUA_TLCL))
// Light C function, Not collectable
#define ttislcf(o) checktag((o), LUA_TLCF)

#define ttisfulluserdata(o) checktag((o), ctb(LUA_TUSERDATA))
#define ttisthread(o) checktag((o), ctb(LUA_TTHREAD))
// This TValue is Point to a Lua Object, and now dead (collected)
#define ttisdeadkey(o) checktag((o), LUA_TDEADKEY)

/* Macros to access values */
// Get value from TValue, 6 member
// GCObject *
#define gcvalue(o) check_exp(iscollectable(o), val_(o).gc)
// void *
#define pvalue(o) check_exp(ttislightuserdata(o), val_(o).p)
// int, for boolean
#define bvalue(o) check_exp(ttisboolean(o), val_(o).b)
// lua_CFunction
#define fvalue(o) check_exp(ttislcf(o), val_(o).f)
// lua_Integer
#define ivalue(o) check_exp(ttisinteger(o), val_(o).i)
// lua_Number
#define fltvalue(o) check_exp(ttisfloat(o), val_(o).n)
// Number, Contain lua_Integer and lua_Number
// if lua_Integer, then convert to lua_Number
#define nvalue(o) check_exp(ttisnumber(o), (ttisinteger(o) ? cast_num(ivalue(o)) : fltvalue(o)))
// All GCUnion Contain a GCObject
// GCObject* point to a TString,
// Get TValue.gc(GCObject*), and convert to TString*
#define tsvalue(o) check_exp(ttisstring(o), gco2ts(val_(o).gc))
// Udata*
#define uvalue(o) check_exp(ttisfulluserdata(o), gco2u(val_(o).gc))
// Closure*
#define clvalue(o) check_exp(ttisclosure(o), gco2cl(val_(o).gc))
// LClosure*
#define clLvalue(o) check_exp(ttisLclosure(o), gco2lcl(val_(o).gc))
// CClosure*
#define clCvalue(o) check_exp(ttisCclosure(o), gco2ccl(val_(o).gc))
// Table*
#define hvalue(o) check_exp(ttistable(o), gco2t(val_(o).gc))
// lua_State*
#define thvalue(o) check_exp(ttisthread(o), gco2th(val_(o).gc))
/* a dead value may get the 'gc' field, but cannot access its contents */
#define deadvalue(o) check_exp(ttisdeadkey(o), cast(void*, val_(o).gc))

#define l_isfalse(o) (ttisnil(o) || (ttisboolean(o) && bvalue(o) == 0))

#define iscollectable(o) (rttype(o) & BIT_ISCOLLECTABLE)

/* Macros for internal tests */
#define righttt(obj) (ttype(obj) == gcvalue(obj)->tt)

#define checkliveness(L, obj) \
  lua_longassert(!iscollectable(obj) || (righttt(obj) && (L == NULL || !isdead(G(L), gcvalue(obj)))))

/* Macros to set values */
// For TValue lua type
#define settt_(o, t) ((o)->tt_ = (t))

#define setfltvalue(obj, x) \
  { \
    TValue* io = (obj); \
    val_(io).n = (x); \
    settt_(io, LUA_TNUMFLT); \
  }

#define chgfltvalue(obj, x) \
  { \
    TValue* io = (obj); \
    lua_assert(ttisfloat(io)); \
    val_(io).n = (x); \
  }

#define setivalue(obj, x) \
  { \
    TValue* io = (obj); \
    val_(io).i = (x); \
    settt_(io, LUA_TNUMINT); \
  }

#define chgivalue(obj, x) \
  { \
    TValue* io = (obj); \
    lua_assert(ttisinteger(io)); \
    val_(io).i = (x); \
  }

#define setnilvalue(obj) settt_(obj, LUA_TNIL)

#define setfvalue(obj, x) \
  { \
    TValue* io = (obj); \
    val_(io).f = (x); \
    settt_(io, LUA_TLCF); \
  }

#define setpvalue(obj, x) \
  { \
    TValue* io = (obj); \
    val_(io).p = (x); \
    settt_(io, LUA_TLIGHTUSERDATA); \
  }

#define setbvalue(obj, x) \
  { \
    TValue* io = (obj); \
    val_(io).b = (x); \
    settt_(io, LUA_TBOOLEAN); \
  }

#define setgcovalue(L, obj, x) \
  { \
    TValue* io = (obj); \
    GCObject* i_g = (x); \
    val_(io).gc = i_g; \
    settt_(io, ctb(i_g->tt)); \
  }

#define setsvalue(L, obj, x) \
  { \
    TValue* io = (obj); \
    TString* x_ = (x); \
    val_(io).gc = obj2gco(x_); \
    settt_(io, ctb(x_->tt)); \
    checkliveness(L, io); \
  }

#define setuvalue(L, obj, x) \
  { \
    TValue* io = (obj); \
    Udata* x_ = (x); \
    val_(io).gc = obj2gco(x_); \
    settt_(io, ctb(LUA_TUSERDATA)); \
    checkliveness(L, io); \
  }

#define setthvalue(L, obj, x) \
  { \
    TValue* io = (obj); \
    lua_State* x_ = (x); \
    val_(io).gc = obj2gco(x_); \
    settt_(io, ctb(LUA_TTHREAD)); \
    checkliveness(L, io); \
  }

#define setclLvalue(L, obj, x) \
  { \
    TValue* io = (obj); \
    LClosure* x_ = (x); \
    val_(io).gc = obj2gco(x_); \
    settt_(io, ctb(LUA_TLCL)); \
    checkliveness(L, io); \
  }

#define setclCvalue(L, obj, x) \
  { \
    TValue* io = (obj); \
    CClosure* x_ = (x); \
    val_(io).gc = obj2gco(x_); \
    settt_(io, ctb(LUA_TCCL)); \
    checkliveness(L, io); \
  }

#define sethvalue(L, obj, x) \
  { \
    TValue* io = (obj); \
    Table* x_ = (x); \
    val_(io).gc = obj2gco(x_); \
    settt_(io, ctb(LUA_TTABLE)); \
    checkliveness(L, io); \
  }

#define setdeadvalue(obj) settt_(obj, LUA_TDEADKEY)

#define setobj(L, obj1, obj2) \
  { \
    TValue* io1 = (obj1); \
    *io1 = *(obj2); \
    (void)L; \
    checkliveness(L, io1); \
  }

/*
** different types of assignments, according to destination
*/

/* from stack to (same) stack */
#define setobjs2s setobj
/* to stack (not from same stack) */
#define setobj2s setobj
#define setsvalue2s setsvalue
#define sethvalue2s sethvalue
#define setptvalue2s setptvalue
/* from table to same table */
#define setobjt2t setobj
/* to new object */
#define setobj2n setobj
#define setsvalue2n setsvalue

/* to table (define it as an expression to be used in macros) */
#define setobj2t(L, o1, o2) ((void)L, *(o1) = *(o2), checkliveness(L, (o1)))

/*
** {======================================================
** types and prototypes
** =======================================================
*/

typedef TValue* StkId; /* index to stack elements */

/*
** Header for string value; string bytes follow the end of this structure
** (aligned according to 'UTString'; see next).
*/
typedef struct TString {
  CommonHeader;
  lu_byte extra; /* reserved words for short strings; "has hash" for longs */
  lu_byte shrlen; /* length for short strings */
  unsigned int hash;
  union {
    size_t lnglen; /* length for long strings */
    struct TString* hnext; /* linked list for hash table */
  } u;
} TString;

/*
** Ensures that address after this type is always fully aligned.
*/
typedef union UTString {
  L_Umaxalign dummy; /* ensures maximum alignment for strings */
  TString tsv;
} UTString;

/*
** Get the actual string (array of bytes) from a 'TString'.
** (Access to 'extra' ensures that value is really a 'TString'.)
*/
#define getstr(ts) check_exp(sizeof((ts)->extra), cast(char*, (ts)) + sizeof(UTString))

/* get the actual string (array of bytes) from a Lua value */
#define svalue(o) getstr(tsvalue(o))

/* get string length from 'TString *s' */
#define tsslen(s) ((s)->tt == LUA_TSHRSTR ? (s)->shrlen : (s)->u.lnglen)

/* get string length from 'TValue *o' */
#define vslen(o) tsslen(tsvalue(o))

/*
** Header for userdata; memory area follows the end of this structure
** (aligned according to 'UUdata'; see next).
*/
typedef struct Udata {
  CommonHeader;
  lu_byte ttuv_; /* user value's tag */
  struct Table* metatable;
  size_t len; /* number of bytes */ // didn't contain the size of Udata struct
  union Value user_; /* user value */
} Udata;

/*
** Ensures that address after this type is always fully aligned.
*/
typedef union UUdata {
  L_Umaxalign dummy; /* ensures maximum alignment for 'local' udata */
  Udata uv;
} UUdata;

/*
**  Get the address of memory block inside 'Udata'.
** (Access to 'ttuv_' ensures that value is really a 'Udata'.)
*/
#define getudatamem(u) check_exp(sizeof((u)->ttuv_), (cast(char*, (u)) + sizeof(UUdata)))

#define setuservalue(L, u, o) \
  { \
    const TValue* io = (o); \
    Udata* iu = (u); \
    iu->user_ = io->value_; \
    iu->ttuv_ = rttype(io); \
    checkliveness(L, io); \
  }

#define getuservalue(L, u, o) \
  { \
    TValue* io = (o); \
    const Udata* iu = (u); \
    io->value_ = iu->user_; \
    settt_(io, iu->ttuv_); \
    checkliveness(L, io); \
  }

/*
** Description of an upvalue for function prototypes
*/
typedef struct Upvaldesc {
  TString* name; /* upvalue name (for debug information) */
  lu_byte instack; /* whether it is in stack (register) */
  lu_byte idx; /* index of upvalue (in stack or in outer function's list) */
} Upvaldesc;

/*
** Description of a local variable for function prototypes
** (used for debug information)
*/
typedef struct LocVar {
  TString* varname;
  int startpc; /* first point where variable is active */
  int endpc; /* first point where variable is dead */
} LocVar;

/*
** Function Prototypes
*/
typedef struct Proto {
  CommonHeader;
  lu_byte numparams; /* number of fixed parameters */
  lu_byte is_vararg;
  lu_byte maxstacksize; /* number of registers needed by this function */
  int sizeupvalues; /* size of 'upvalues' */
  int sizek; /* size of 'k' */
  int sizecode;
  int sizelineinfo;
  int sizep; /* size of 'p' */
  int sizelocvars;
  int linedefined; /* debug information  */
  int lastlinedefined; /* debug information  */
  TValue* k; /* constants used by the function */
  Instruction* code; /* opcodes */
  struct Proto** p; /* functions defined inside the function */
  int* lineinfo; /* map from opcodes to source lines (debug information) */
  LocVar* locvars; /* information about local variables (debug information) */
  Upvaldesc* upvalues; /* upvalue information */
  struct LClosure* cache; /* last-created closure with this prototype */
  TString* source; /* used for debug information */
  GCObject* gclist;
} Proto;

/*
** Lua Upvalues
*/
typedef struct UpVal UpVal;

/*
** Closures
*/

#define ClosureHeader \
  CommonHeader; \
  lu_byte nupvalues; \
  GCObject* gclist

typedef struct CClosure {
  ClosureHeader;
  lua_CFunction f;
  TValue upvalue[1]; /* list of upvalues */
} CClosure;

typedef struct LClosure {
  ClosureHeader;
  struct Proto* p;
  UpVal* upvals[1]; /* list of upvalues */
} LClosure;

typedef union Closure {
  CClosure c;
  LClosure l;
} Closure;

#define isLfunction(o) ttisLclosure(o)

#define getproto(o) (clLvalue(o)->p)

/*
** Tables
*/

typedef union TKey {
  struct {
    TValuefields;
    int next; /* for chaining (offset for next node) */
  } nk;
  TValue tvk;
} TKey;

/* copy a value into a key without messing up field 'next' */
#define setnodekey(L, key, obj) \
  { \
    TKey* k_ = (key); \
    const TValue* io_ = (obj); \
    k_->nk.value_ = io_->value_; \
    k_->nk.tt_ = io_->tt_; \
    (void)L; \
    checkliveness(L, io_); \
  }

typedef struct Node {
  TValue i_val;
  TKey i_key;
} Node;

// every time set table with new key (means t[key] == nil before set)
// flags will be seted to 0, using invalidateTMcache
typedef struct Table {
  CommonHeader;
  lu_byte flags; /* 1<<p means tagmethod(p) is not present */
  lu_byte lsizenode; /* log2 of size of 'node' array */
  unsigned int sizearray; /* size of 'array' array */ // should be 2^n after rehash
  TValue* array; /* array part */
  Node* node;
  Node* lastfree; /* any free position is before this position */
  struct Table* metatable;
  GCObject* gclist;
} Table;

/*
** 'module' operation for hashing (size is always a power of 2)
*/
// s is the hash code, lmod get last log2(size) - 1 bits
#define lmod(s, size) (check_exp((size & (size - 1)) == 0, (cast(int, (s) & ((size)-1)))))

#define twoto(x) (1 << (x))
#define sizenode(t) (twoto((t)->lsizenode))

/*
** (address of) a fixed nil value
*/
#define luaO_nilobject (&luaO_nilobject_)

LUAI_DDEC const TValue luaO_nilobject_;

/* size of buffer for 'luaO_utf8esc' function */
#define UTF8BUFFSZ 8

LUAI_FUNC int luaO_int2fb(unsigned int x);
LUAI_FUNC int luaO_fb2int(int x);
LUAI_FUNC int luaO_utf8esc(char* buff, unsigned long x);
LUAI_FUNC int luaO_ceillog2(unsigned int x);
LUAI_FUNC void luaO_arith(lua_State* L, int op, const TValue* p1, const TValue* p2, TValue* res);
LUAI_FUNC size_t luaO_str2num(const char* s, TValue* o);
LUAI_FUNC int luaO_hexavalue(int c);
LUAI_FUNC void luaO_tostring(lua_State* L, StkId obj);
LUAI_FUNC const char* luaO_pushvfstring(lua_State* L, const char* fmt, va_list argp);
LUAI_FUNC const char* luaO_pushfstring(lua_State* L, const char* fmt, ...);
LUAI_FUNC void luaO_chunkid(char* out, const char* source, size_t len);

#endif
